Power-hammer.



UNITED STATES PATENT OFFICE.

SAMUEL A. THORNBURG, F FRONTENAC, KANSAS, ASSIGNOR 0F ONE-HALF 'IOARTHUR J'. FLETCHER, OF FRONTENAC, KANSAS.

POWER-HAMMER.

Specification of Letters Patent.

Patented Oct. 31, 19 11.

by means of a toggle lever; and the objects of the same are to simplifythe construction of such a machine by reducing its number of parts andthe size of the whole, and to provide readily accessible means foradjusting the rapidity, length of throw, and power of the stroke. Theseobjects are accomplished by the construction described and claimedbelow, and as shown in the draw-v ings wherein Figure 1 is a frontelevation of this machine complete, partly broken away. Fig.

2 is an edge view thereof. Fig. 3 is a plan view of the shackleconnecting the toggle levers, illustrating the means for adjusting thetension of the spring.

In the drawings the numeral 1 designates the base from which risestandards 2 con.- nected by cross bars 3 which carry guides 4 in whichthe hammer head 5 moves vertically, and this head carries the hammer orupper die 6 which coacts with the anvil or bed die 7 in a manner wellknown in this art. The rollers 10 move astride the standard 2 and arejournaled in a bracket 11 which projects to the rear from a verticallymovable yoke 12. The power wheel is here indicated at as a pulley,loosely belted as at 21 to another pulley 22 on a crank shaft 23 whosecrank 24 is connected with a pitman 25 having an eccentric band 26 atits lower end which is mounted on an eccentric 26 ournaled in the yoke12 in' any suitable manner. Through the front and rear plates of thisyoke is ournaled a shaft 27 having a handle 28 fast on its forward endand movable over a toothed segment 29 so as to adjust the position ofthe handle and shaft. Between the plates of the yoke said shaft issecured as at 30 within the eccentric head 26 as by squaring the shaftand the hole through the eccentric, or by a key as shown, or in anysuitable manner. It follows that adjustment of the handle turns theeccentric and alters the vertical path of movement of the yoke withrespect to the rise and fall of the crank 24. The connection between thehammer head and the arms of the yoke is duplicated at each side of thelatter, and a description of that at one side will suffice for both.vEars project from the sides of said head, and to each of them at 41 ispivoted one arm or link 42 of the toggle, the other arm or link 43 beingpivoted to this arm at 44 and rising therefrom between the face platesof the yoke 12 in whose lower end this link 43 is pivoted as at.45; andsaid arm is forked at its upper end as at 46. Between the arms of thefork is pivoted the outer end of a rod 47 (see Fig. 3) whose inner endis threaded and has a nut 48. Between the arms of the opposite fork 46is pivoted a shorter rod 47 whose inner end connects with a shackle 49at the bend thereof, while the arms of this shackle are connected attheir remote ends by a plate 50 which is held upon said arms by nuts 48the center of the plate having a hole 51 for the passage of the rod 47Around the latter between this plate and a similar plate 50 mounted onthe rod inside its nut 48, is coiled an expansive spring 52, and it willbe obvious that the normal tendency of this spring is to draw the forkedextremities 46 of the upper links 43 of the toggle levers toward eachother, and spread their lower ends apart at 44. By setting the nuts 48and 48*, the tension of the spring can be adjusted; and by removing thenuts the spring can be replaced by one of greater or less length orpower.

A pedal is pivoted to the base 1 and connected by a rod 61 with a belttightener 62 which when depressed throws tension on the belt 61 anddrives the pulley 22 from the power wheel 20.

It is obvious that any suitable type of belt fastener, speed changer,fast and loose pulleys, or other connecting and disconnecting mechanismmight be substituted without departing from the spirit of my invention.

In operation, when the pedal is depressed the belt tightener causes thepulley 22 and its crank 24 to rotate, and the pitman 25 causes the yoke12 to rise and fall as rapidly as the crank rotates. This rapidity maybe regulated to some extent by the speed with which the power wheel 20revolves and to some further extent by the tension imparted to the belttightener, for the latter might be permitted to be loose so as to allowa little slipping of the belt. Adjustment of the handle or lever 28adjusts the path through which the yoke rises and falls, but not thedegree or extent of its rise and fall; but as the yoke carries the othermechanism connecting it with the hammer head, if the yoke is caused tomove through a higher path it will be obvious that the upper die 6 willbe correspondingly adjusted and the machine can operate upon thickerwork. Hence we have accounted for the speed of rotation and the paththrough which the hammer moves. As the crank makes an upward stroke allmovable parts of the mechanism rise. As the crank makes its downwardstroke, the yoke descends rapidly as the hammer head has not yet lostthe inertia of its previous upward stroke. The result is that thedescending pivots 45 move the upper toggle links 43 downward while thelower toggle links 42 stand practically idle for a moment until thepivots 44 have moved past a horizontal line through the pivots 41, theexpansion of the spring 52 assisting. As the movable parts reach thelower limit of their stroke, the lower pivots 44 exert a clownwardtension on the then upper pivots 41, and the hammer head 5 is given asudden down ward impulse and caused to strike a forcible blow upon theanvil. In making its blow the hammer head causes the inner ends of thelinks 42 to pass again below their outer ends let as the latter start onthe next upward movement with the yoke, and the rebound of the hammerhead starts it then upward so that it follows the yoke and the ascendingmechanism, and the operation is repeated.

It is obvious that by adjusting the tension of the spring, the force ofthe blow can to a considerable extent be adjusted.

It will be clear to those familiar with this art that the dies can bechanged at will so that this machine can be used either as a powerhammer or for any other purpose of which it is susceptible.

I do not confine myself to the materials or shapes or proportions ofparts, and considerable change in details may be made without departingfrom the principle of my invention.

\Vhat is claimed is 1. I11 a power hammer, the combination with a yoke,means for reciprocating it vertically, upright guides, and a hammer headmovable therein; of links pivoted to said head and leading from itsopposite sides, an upright link pivoted at its lower end to the outerend of each of said other links and forming therewith a toggle lever,each upright link being pivoted. near its upper end to said yoke, and ayielding means for drawing the upper extremities of these upright linkstoward each other connecting the upper extremities of the said links.

2. In a power hammer, the combination with a yoke, means forreciprocating it vertically, upright guides, and a hammer head movabletherein; of links pivoted to said head and leading from its oppositesides, an upright link pivoted at its lower end to the outer end of eachof said other links and forming therewith a toggle lever, each uprightlink being pivoted near its upper end to said yoke, rods connecting theupper extremities of said upright links, a shackle attached to the innerend of one rod with its arms lapping the other rod, a plate across theextremity of the last-named rod, a plate across the ends of the shacklearms, means for adjusting both said plates, and an expansive springbetween them.

In testimony that I claim the foregoing as my own, I have hereto aflixedmy signature in the presence of two witnesses.

SAMUEL A. THORNBURG.-

lVitnesses JOHN I'IADERLEIN, KATIE HADERLEIN.

Copies of this patent may be obtained for five cents each, by addressingthe Commissioner of Patents,

Washington, D. G.

